- /* if we extend to eof, continue to block boundary */
- if (off + len == src->i_size)
+ /*
+ * If we extend to eof, continue to block boundary if and only if the
+ * destination end offset matches the destination file's size, otherwise
+ * we would be corrupting data by placing the eof block into the middle
+ * of a file.
+ */
+ if (off + len == src->i_size) {
+ if (!IS_ALIGNED(len, bs) && destoff + len < inode->i_size)
+ goto out_unlock;